Garfield Logan's Origin and Powers
Garfield's birth parents were anthropologists who brought him with them to High Lamumba, an African country where they were conducting some research. While there, Gar contracted a tropical illness -the Sakutia- that was
fatal to man, but not animals. His father combined modern technology and wisdom from the local shaman to erect a machine which injected a serum into Gar. This serum combined genetic material from both animals and humans. It cured Gar of the Sakutia, but had unpredicted side-effects. First noticed, it turned Garfield's skin a very obvious kelly green. Secondly, Garfield Logan aquired the ability to change into any animal he desired by sheer force of will. The metamorphosis is near instantaneous, occurring with a brief flash of light. Whatever animal he turns into though remains green, and he is able to speak like normal irregardless of his shape. He's been known to turn into many animals including a rhinocerous, elephant, eagle, housefly, tiger, gorilla, and pretty much anything one might find in a zoo is possible. He can do this in about the time it takes for someone to tell a very bad animal-related pun. Which he does quite often.

Garfield Logan's History
Soon after his recovery, Gar's parents died in an accident,
and Gar was raised by the king of a local tribe : Tawana. Unfortunately the young Garfield Logan was noticed by some criminals who took him from the island, away from the only world he ever truly knew, and forced Gar to perform criminal acts for their own selfish ends. The Doom Patrol thwarted these criminals, and took Garfield under their wing. Rita Farr and her husband Steve Dayton adopted him. Gar joined the Doom Patrol as Beast Boy.

Garfield Logan's Second ChanceMarv Wolfman and George Perez were given the task some years later of revitalizing a comic book series called the Teen Titans which was originally just a cheesy comic book about the exploits of the young sidekicks of more famous superheroes like Batman, Wonder Woman, Green Arrow and The Flash. Wolfman and Perez took the idea of Teen Titans and expanded upon it, creating in the early 1980s what became one of the best written and drawn comic book series of all time. In this series, they breathed new life into the character of Garfield Logan. Thus continues his story.

Garfield Logan had nearly full access to his father's vast wealth, but it was empty and hollow. Garfield Logan used his powers and talents to escape his sad and lonely family life, and through humor and a devil-may-care attitude which hid his darker side, he spent a short time in Hollywood as a stuntman and actor, and he starred in a number of low budget action and horror films which made him a small fortune of his own. However the fame wore thin on his impatience and left a cold, empty feeling inside.

Logan sought out solace and refuge in a makeshift family of misfits like himself: he became one of the founding members of The New Teen Titans. He made very good friends there, including Cyborg, Nightwing, Troia, Jericho, Starfire, Raven and Kid Flash. Together they had many adventures and saved many lives. Changeling was also a useful combatant for and protector of world in Crisis on Infinite Earths in 1985. Garfield Logan also fell in love for a time with Tara Markov aka Terra, but this romance was short-lived because Tara turned out to be more screwed up in the head than he was.

In the early days of the New Teen Titans, Gar was always fooling around. He felt that as the youngest member of the group at the time, somebody had to inject humor and levity into what was otherwise usually very serious and dangerous situations the young super heroes were compelled to undertake. This false bravado also masked a lot of emotions that he just couldn't deal with, involving the lost of both his parents and step parents, and the fact that despite all his wealth and power, he was uniquely alone in the universe and unfulfilled.

As time progressed, the life outside his red and white costume slowly began to crush him. His step father went quite mad. The woman he came to love betrayed him and the entire team. Garfield learned more about the deaths of his step parents and became obsessed with revenge and justice. Slowly he lost his light-hearted facade and a darker, more twisted Changeling began to appear. Gone were the wisecracks, pranks and smart alecky remarks.

In short, he stopped being fun. And I stopped reading. Last I heard, Garfield Logan had left the Teen Titans. His current whereabouts are undocumented.